A method utilizing high-pressure liquid chromatography has been developed for the separation and quantitation of the hydrolytic products of UDPG1cNAc. The method is being applied to test whether the hydrolysis of UDPG1cNAc is a biochemical criterion for the transformation of embryonic cells of the rat and hamster by carcinogenic fluorenylhydroxamic acids. Determination of the binding constants of the carcinogen, 2-FAA, and of its noncarcinogenic isomer, 3-FAA, to hepatic cytochrome P1-450 of rats indicates that 3-FAA inhibits the binding of 2-FAA competitively. This finding has prompted an investigation as to whether 3-FAA inhibits the microsomal oxidation of 2-FAA, including its N-hydroxylation. Oral administration of 2-FAA to the rat induces a new hemoprotein separable from cytochrome P-450 by gel electrophoresis and precipitable by ammonium sulfate. Preliminary evidence suggests that the induced protein increases N-hydroxylation of 2-FAA. The purification of the induced protein is in progress. The synthesis and reactivity of the presumed ultimate carcinogen, N-acetoxy-2-fluorenamine, is being explored. N-Carbobenzoxy-N-acetoxy-2-fluorenamine has been synthesized as an intermediate. Removal of the carbobenzoxy group yielded 2-fluorenyl-acetamide. The mechanism of this intramolecular acetyl transfer is under investigation. Attempts are being made to trap N-acetoxy-2-fluorenamine presumed to be the intermediate of the rearrangement.